Hermetic electrical feedthrough assembly for a compressor and method for making the same

ABSTRACT

An electrical feedthrough assembly for providing connection to components of a compressor. The electrical feedthrough assembly includes a housing having an inner surface defining a channel. A sealed wire assembly is provided in the channel. The sealed wire assembly includes a body having an outer surface defining a groove and a plurality of wires sealingly passing through the body. An o-ring fits in the groove to provide a hermetic seal between the body and the inner surface of the housing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject disclosure relates to compressors, and more particularly toan improved method for providing electrical connections to componentswithin the shell or housing of a compressor.

2. Background of the Related Art

Referring to FIG. 1, a top, partial cross-sectional view of a prior artcompressor 100 is shown. The compressor 100 has a shell 110 thatprovides a hermetically sealed environment. Use of electrical componentsinside the shell 110 has been widely used and well understood in theart. Great care must be taken to insure that the integrity of thehermetically sealed environment is not breached by the electricalconnections.

A power terminal 112 facilitates electrical connection into thehermetically sealed environment of the shell 110. The power terminal 112must maintain the seal while withstanding the harsh operatingconditions. The power terminal 112 is disposed within an aperture in theshell 110. The power terminal 112 has a cup-shaped metal collar 126 witha bottom wall. The wall defines holes that conductor pins 128 passthrough. The collar 126 is sealed in the shell aperture by welding andthe pins 128 are sealed within the collar 126 by fused glass insulation.To further stabilize the terminal 112, the fused glass insulationsurrounding the pins 128 is commonly covered with epoxy or shielded byceramic collars.

A fence 130 surrounds and protects the power terminal 112. A molded plug(not shown) is configured to couple with the fence 130 and, thereby,make an electrical connection with the pins 128 outside the shell 110.To accomplish this connection, the pins 128 are often provided with atab (not shown). A similar plug, tabs or wires must be provided on theinner end of the pins 128 to accomplish electrical connection betweenthe compressor component and the power terminal 112.

There are problems associated with sealed glass pin power terminals 112.The terminals 112 require extensive tooling that is costly and noteasily modified to add or subtract pins 128. This prefabrication processis costly, complex and time consuming. As the terminals 112 are beingwelded to the shells 110, the glass seals are often damaged and, thus,the assembly 120 must be scraped and replaced. This is quite costly assignificant time and expense has already been invested in pre-assemblingthe power terminal 112. Even worse, damaged glass seals go undetected,creating eventual compressor failure. Further, it is common for the plugand, in turn, electrical connections to become loose resulting incompressor failure. These additional parts and complexity to connect tothe pins 128 adds cost and creates additional junctions that may fail.For other examples, see U.S. Pat. Nos. 6,971,860; 6,372,993; 5,584,716;5,762,479; 5,538,404; 5,281,105; 4,729,723; 4,412,791; 4,406,590;4,396,360; 4,384,635; and 4,239,461.

There is a need, therefore, for an improved assembly and method ofmaking the assembly which permits easy internal and external electricalconnections with the hermetically sealed environment within a compressorshell and aids in assuring reliable performance while being costeffective.

SUMMARY OF THE INVENTION

It is an object of the subject technology to provide an electricalassembly that can effectively provide connection to compressorcomponents yet maintain the integrity of the compressor shell throughharsh conditions such as swings in vacuum and pressure.

It is another object of the subject technology to simplify assembly ofcompressors and the compressor components by eliminating the glasssealed power terminal. It is another object of the subject technology toprovide an electrical feedthrough assembly that can accommodatemodifications such as additional wires.

The present invention is directed to an electrical feedthrough assemblyfor providing connection to components of a compressor. The electricalfeedthrough assembly includes a housing having an inner surface defininga channel. A sealed wire assembly is provided in the channel. The sealedwire assembly includes a body having an outer surface defining at leastone groove and a plurality of wires sealingly passing through the body.An o-ring fits in the groove(s) to provide a hermetic seal between thebody and the inner surface of the housing.

Another embodiment is directed to a compressor including a shelldefining an opening. A weld housing has an outer surface hermeticallywelded in the opening. The weld housing forms an elongated channel tohold a sealed wire assembly. The sealed wire assembly includes a bodyhaving an outer surface defining a groove and wires sealingly passingthrough the body. An o-ring is disposed in the groove to provide ahermetic seal between the body and the weld housing.

Still another embodiment of the present invention includes a compressorincluding a shell defining an opening and a wire assembly hermeticallysealed in the opening. The wire assembly includes a body and wirespassing through the body, wherein the body is an epoxy material thathermetically seals the wires directly therein without additionalcomponents. Preferably, the body has an outer surface defining at leastone groove that receives an o-ring. Additionally, the compressor mayhave a housing with an outer surface hermetically secured to the openingand an inner surface defining an elongated channel for receiving thewire assembly.

It should be appreciated that the present invention can be implementedand utilized in numerous ways, including without limitation as aprocess, an apparatus, a system, a device, and a method for applicationsnow known and later developed. These and other unique features of theembodiments disclosed herein will become more readily apparent from thefollowing description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the disclosedsystem appertains will more readily understand how to make and use thesame, reference may be had to the following drawings.

FIG. 1 is a top, partial cross-sectional view of a prior art compressor.

FIG. 2A is an outer perspective view of an electrical feedthroughassembly for a compressor in accordance with the subject technology.

FIG. 2B is an inner perspective view of an electrical feedthroughassembly for a compressor in accordance with the subject technology.

FIG. 3 is a perspective view of a weld housing for the feedthroughassembly of FIG. 2.

FIG. 4 is a side, cross-sectional view of the weld housing of FIG. 3.

FIG. 5 is a perspective view of a sealed wire assembly for thecompressor feedthrough assembly of FIG. 2, wherein the sealed wireassembly is ready to be inserted in a weld housing.

FIG. 6 is a side view of the sealed wire assembly of FIG. 5.

FIG. 7 is a side view of the sealed wire assembly of FIG. 5 with theo-rings and snap ring removed.

FIG. 8 is an end view of the sealed wire assembly of FIG. 5.

FIG. 9 is a plan view of a snap ring for use on the body of the sealedwire assembly of FIG. 5.

FIG. 10 is a plan view of an o-ring for use on the body of the sealedwire assembly of FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention overcomes many of the prior art problemsassociated with providing electrical connections to components withinthe shell of a compressor. The advantages, and other features of thetechnology disclosed herein, will become more readily apparent to thosehaving ordinary skill in the art from the following detailed descriptionof certain preferred embodiments taken in conjunction with the drawingswhich set forth representative embodiments of the present invention andwherein like reference numerals identify similar structural elementswhenever possible.

All relative descriptions herein such as above, below, left, right, up,and down are with reference to the Figures, and not meant in a limitingsense. Relative descriptions such as inner and inward are with referenceto being a direction toward the interior of a compressor shell whereasouter and outward are a direction away from the compressor. Theillustrated feedthrough assemblies can be understood as providingexemplary features of varying detail of certain embodiments, andtherefore, components, modules, elements, and/or aspects of theillustrations can be otherwise added to, combined, interconnected,sequenced, separated, interchanged, positioned, and/or rearrangedwithout materially departing from the disclosed systems or methods.Additionally, the shapes and sizes of components are also exemplary andunless otherwise specified, can be altered without materially affectingor limiting the disclosed technology.

Referring to FIGS. 2A and 2B, outer and inner perspective views,respectively, of an electrical feedthrough assembly 10 for a compressorin accordance with the subject technology are shown. In brief overview,the feedthrough assembly 10 includes a weld housing 20 sealinglyretaining a sealed wire assembly 40. The outer surface of the weldhousing 20 is hermetically welded within an opening of a compressorshell (not shown). A plurality of wires 42 extend through the wireassembly 40 to interconnect electrical components within the compressorshell with electrical components outside the compressor shell.

Now referring to FIGS. 3 and 4, perspective and side cross-sectionalviews, respectively, of the weld housing 20 are shown. The weld housing20 has a central portion 22 that defines an inner channel 24. The length28 of the inner channel 24 is relatively longer than the thickness of acompressor shell and the bottom wall of a traditional metal collar.Thus, the inner channel 24 provides significantly more surface area 26for the wire assembly 40 to seal against. The outer neck 30 of the weldhousing 20 narrows such that even if dislodged, the wire assembly 40would be retained against internal pressure of the compressor. The innerend 32 of the weld housing 30 expands in diameter. As a result, if theweld housing 20 were to become dislodged, the compressor shell wouldretain the weld housing 20 against internal compressor pressure. Theweld housing 20 is welded into the opening in the compressor shell bythe central portion 22 adjacent inner end 32.

For exemplary purposes only, the weld housing 20 is depicted as having agenerally circular configuration. Those skilled in the art will readilyappreciate however, that the subject disclosure is not limited to a weldhousing having such a configuration. Indeed, it is envisioned and wellwithin the scope of the subject disclosure that the weld housing couldtake form in any shape. Without limitation, such shapes could include asquare, triangle, rectangle, oval as viewed from a side, from above, orfrom below. The weld housing 20 can be formed from various materialssuch as plastic and/or metals like, without limitation, brass, aluminumand steel.

Referring now to FIGS. 5 and 6, perspective and side views,respectively, of the sealed wire assembly 40 are shown, wherein the wireassembly 40 is ready to be inserted into the weld housing 20. As bestseen in FIGS. 2A and 2B, a body 44 of the wire assembly 40 is relativelylonger than the weld housing 20 so that, when assembled, an innerportion 50 and an outer portion 52 of the body 44 extend from the weldhousing 20. The outer portion 52 of the body 44 is shapedcomplimentarily to nestle within the outer neck 30 of the weld housing20.

Referring now to FIG. 7, a side view of the sealed wire assembly of FIG.5 with the snap ring 56 and o-rings 58 removed is shown. The outerportion 52 includes a slot 54 for receiving the snap ring 56 as shown inFIG. 9. When disposed in the slot 54, the snap ring 56 prevents the body44 from moving inward in the weld housing 20. Preferably, the snap ring56 is carbon steel with an oil dip coating or stainless steel. The outersurface 46 of the body 44 also defines two o-ring grooves 48 that arewithin the central portion 22 of the weld housing 20, when assembled.Each groove 48 receives an o-ring 58 (as shown in FIG. 10) to create ahermetic seal with the central portion 22. The o-rings 58 may beresiliently flexible material such as parker compound C8873-70 availablefrom Parker-Hannifin Corp. of Cleveland, Ohio.

Referring now to FIGS. 6-8, the body 44 also defines three passages 60,each of which carries a wire 42. The wires 42 are effectively buried andfixed in the body passages 60 such that the seal around the wires ishermetic. The body 44 may be fabricated from a material such as an epoxymaterial, a ceramic material and the like.

To assemble the feedthrough assembly 10 in the shell of a compressor, anempty weld housing 20 is welded into an opening in the shell. Thedesired number of wires 42 are embedded in the body 44. The o-rings 58are placed in the respective groove 48, then the inner ends 64 of thewires 42 are connected to the compressor components. The outer ends 66of the wires 42 are routed through the weld housing 20. The body 44 isdisposed within the weld housing 20 such that the o-rings 58 form ahermetic seal with the weld housing 20. To further secure the body 44 inthe weld housing 20, the snap ring 56 clips into the slot 54.

It is envisioned that many techniques, now known and later developed,can successfully accomplish the hermetic seals required to practice thesubject technology. For example, the weld housing 20 does not have to bewelded to the shell, rather the weld housing 20 could be epoxied, glued,press-fit, form a groove that retains an o-ring or otherwisehermetically affixed within the opening. Similarly, the body 44 could besealed with the weld housing 20 simply by being oversized and formedfrom a material that has sealing properties such that no o-rings areneeded. This compression fit within the weld housing 20 could providesealing pressure on the wire 42 as well. Epoxy, interference fits, glueand the like could also sealingly hold the body 44 in place.

The body 44 could also shaped to be held in place by outward pressuresuch that the snap ring is unnecessary. As can be seen, the body 44 canbe easily replaced to include additional wires in the event thatadditional electrical connections are desired. In the case where thecompressor shell is thick enough, the body 44 may be sized andconfigured to directly seal to the shell without a weld housing.

As would be appreciated by those of ordinary skill in the pertinent art,the subject technology is applicable to use as in any type of compressorwith significant advantages for hermetically sealed portions thereof.The functions of several elements may, in alternative embodiments, becarried out by fewer elements, or a single element. Similarly, in someembodiments, any functional element may perform fewer, or different,operations than those described with respect to the illustratedembodiment. Also, functional elements shown as distinct for purposes ofillustration may be incorporated within other functional elements,separated in different hardware or distributed in various ways in aparticular implementation. Further, relative size and location aremerely somewhat schematic and it is understood that not only the samebut many other embodiments could have varying depictions.

INCORPORATION BY REFERENCE

All patents, published patent applications and other referencesdisclosed herein are hereby expressly incorporated in their entiretiesby reference.

While the invention has been described with respect to preferredembodiments, those skilled in the art will readily appreciate thatvarious changes and/or modifications can be made to the inventionwithout departing from the spirit or scope of the invention as definedby the appended claims.

1. An electrical feedthrough assembly for providing connection to atleast one component of a compressor, the electrical feedthrough assemblycomprising: a housing having an inner surface defining a channel; asealed wire assembly at least partially in the channel, the sealed wireassembly including: a substantially solid body having an outer surfacedefining a groove; at least one wire sealingly passing through the body;an o-ring disposed in the groove to provide a hermetic seal between thebody and the inner surface of the housing; and a snap ring for couplingto a slot formed in the body to prevent the sealed wire assembly frommoving axially in a first direction in the housing.
 2. An electricalfeedthrough assembly as recited in claim 1, wherein the housing has anouter surface adapted to be sealingly welded to a compressor shell. 3.An electrical feedthrough assembly as recited in claim 1, wherein thehousing has an enlarged end and a narrowed end.
 4. An electricalfeedthrough assembly as recited in claim 1, further comprising a secondo-ring disposed in a second groove formed in the body.
 5. An electricalfeedthrough assembly as recited in claim 1, wherein the at least onewire is four wires.
 6. An electrical feedthrough assembly as recited inclaim 1, wherein the body has a length greater than a length of thehousing.
 7. An electrical feedthrough assembly as recited in claim 6,wherein the body has a portion positioned outside the housing, theportion of the body positioned outside the housing being configured toreceive an end portion of the housing to prevent the sealed wireassembly from moving axially in one direction in the housing.
 8. Anelectrical feedthrough assembly as recited in claim 1, wherein thehousing and sealed wire assembly being configured and positioned tosubstantially limit axial movement of the sealed wire assembly in thehousing.
 9. A compressor comprising: a shell defining an opening; a wireassembly hermetically sealed in the opening, the wire assembly includinga substantially solid body and at least one wire passing through thebody, the body being formed from a material that hermetically seals theat least one wire directly in the body without additional components andthe body having an outer surface defining a groove; and the wireassembly comprising: a housing having an outer surface hermeticallysecured to the opening and an inner surface defining an elongatedchannel for receiving the body; an o-ring positioned in the groove tocontact the elongated channel to form a hermetic seal; and a snap ringfor coupling to a slot formed in the body to prevent the body frommoving axially in the housing in a first direction.
 10. A compressor asrecited in claim 9, wherein the material is selected from the groupconsisting of epoxy, a ceramic and combination thereof.
 11. A compressoras recited in claim 9, wherein the wire assembly is configured andpositioned to substantially limit axial movement of the body relative tothe shell.
 12. A compressor as recited in claim 9, wherein the body hasa length greater than a length of the housing.
 13. A compressor asrecited in claim 9, wherein the housing comprises a first end and asecond end opposite the first end, the first end is positioned in theshell and has a diameter greater than the opening.
 14. A compressor asrecited in claim 13, wherein the elongated channel is positioned betweenthe first end and the second end.
 15. A compressor as recited in claim14, wherein the body has a first portion positioned outside the secondend of the housing, the first portion of the body being configured toreceive the second end of the housing to prevent the sealed wireassembly from moving axially in a second direction in the housingopposite the first direction.
 16. A compressor as recited in claim 15,wherein the slot is formed in the first portion of the body.
 17. Amethod for electrically connecting components within a shell of acompressor, the method comprising: forming an opening in the shell;hermetically sealing a housing in the opening, the housing having anelongated inner surface defining a channel; embedding at least one wirein a body such that the at least one wire is hermetically sealed in thebody to form a wire assembly; placing an o-ring in a respective groovein the body; connecting an end of the at least one wire to a componentwithin the shell of the compressor; securing the wire assembly withinthe channel such that the housing is hermetically sealed about the wireassembly with the o-ring; and preventing the body from moving axially inthe housing in a first direction by coupling a snap ring to a slotformed in the body.